Pelletized carbonized biomass, methods, and apparatuses

ABSTRACT

Pelletized carbonized biomass-based fuel products, methods, and apparatuses are provided. Methods include applying a binder and a first amount of water to at least partially carbonized biomass, applying a second amount of water to the at least partially carbonized biomass, and pelletizing the at least partially carbonized biomass in an inert atmosphere. Apparatuses include a feeder of at least partially carbonized biomass, a binder source and a first water source configured to provide a binder and water to the at least partially carbonized biomass, a second water source downstream of the binder and first water sources, a pelletizer configured to receive and pelletize the at least partially carbonized biomass, and an inert gas source configured to provide inert gas to the pelletizer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/915,431, filed Jun. 11, 2013, now U.S. Pat. No.9,399,744, which claims the benefit of U.S. Provisional Application No.61/658,396, filed Jun. 11, 2012, and U.S. Provisional Application No.61/813,069, filed Apr. 17, 2013, each of which is incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present invention relates generally to the field of fuel products,and more particularly to pelletized carbonized biomass-based fuelproducts and methods and apparatuses for producing the same.

BACKGROUND

Biomass-based fuel products are desirable because they provide arenewable energy source and an eco-friendly alternative to coal andother fossil fuels. Processes such as torrefaction are known to produceat least partially carbonized biomass-based fuel products offeringincreased energy value and improved combustion properties over the rawbiomass.

Densification and pelletization processes are known to transform the atleast partially carbonized biomass into more useful forms for storage,shipping, and handling. Densification and pelletization processes,however, experience problems. It would therefore be desirable to provideimproved methods and apparatuses for producing pelletized, carbonizedbiomass-based fuel products.

SUMMARY

In one aspect, a method for producing a pelletized fuel product isprovided. The method includes pelletizing at least partially carbonizedbiomass in an inert atmosphere. In one embodiment, a method forproducing a pelletized fuel product includes applying a binder to atleast partially carbonized biomass, applying a first amount of water tothe at least partially carbonized biomass, applying a second amount ofwater to the at least partially carbonized biomass after applying thebinder and the first amount of water, and thereafter pelletizing the atleast partially carbonized biomass in an inert atmosphere.

In another aspect, an apparatus for producing a pelletized fuel productis provided. The apparatus includes a feeder of at least partiallycarbonized biomass, a pelletizer configured to receive and pelletize theat least partially carbonized biomass, and an inert gas sourceconfigured to provide inert gas to the pelletizer. In one embodiment, anapparatus for producing a pelletized fuel product includes a feeder ofat least partially carbonized biomass, a binder source configured toprovide a binder to the at least partially carbonized biomass, a firstwater source configured to moisten the at least partially carbonizedbiomass to a moisture content of about 20 percent to about 40 percent byweight, a second water source configured to bring the moisture contentof the at least partially carbonized biomass to about 40 percent toabout 60 percent by weight, a pelletizer configured to receive andpelletize the at least partially carbonized biomass, and an inert gassource configured to provide inert gas to the pelletizer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating one embodiment of anapparatus for producing a pelletized fuel product.

FIG. 2 is a schematic diagram illustrating one embodiment of anapparatus for producing a pelletized carbonized biomass fuel product.

DETAILED DESCRIPTION

The present application will now be described more fully hereinafterwith reference to the accompanying drawings, in which severalembodiments of the application are shown. Like numbers refer to likeelements throughout the drawings.

In the following description, numerous specific details are given toprovide a thorough understanding of embodiments. The embodiments can bepracticed without one or more specific details, or with other methods,components, materials, and the like. In other instances, well knownstructures, materials, or operations are not shown or described indetail to avoid obscuring aspects of the embodiments.

Reference throughout the specification to “one embodiment,” “anembodiment,” or “embodiments” means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, the appearances of thephases “in one embodiment” or “in certain embodiments” in various placesthroughout the specification are not necessarily referring to the sameembodiment. Furthermore, the particular features, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Carbonization processes are known that convert organic substances intocarbon or carbon-containing residue. As used herein, the terms“carbonize” and “carbonized” refer to these processes and theirproducts. For example, processes such as torrefaction and hydrothermalcarbonization convert raw biomass to at least partially carbonizedproducts having increased mass energy density.

As used herein, the term “biomass” refers to renewable organic materialssuch as biological materials comprising lignocellulose includinghardwood and softwood from trees, wood chips, slash or hog fuel fromsoftwood tree processing, forest residue, straw, chaff, grain, grasses,corn, corn husk, weeds, aquatic plants, and hay, and lignocellulosecontaining material of biological origin, such as some municipal wasteor household waste. Woody biomass is mainly composed of hemicellulose,cellulose, lignin, and small amounts of ash. The structure is a complexarrangement of microfibrils, or bundles of cellulose covered withhemicellulose. Lignin fills the voids between the microfibrils and issometimes embedded within the amorphous portions of the microfibrils.Each component of the woody biomass displays a unique thermal stability,with hemicellulose decomposing between 225 and 325° C., cellulosedecomposing between 305 and 375° C., and lignin decomposing between 250and 500° C.

Torrefaction refers to the heating of biomass to produce a producthaving increased mass energy density that can be used as a fuel.Generally, torrefaction may be performed on biomass at temperaturesbetween about 200° C. and about 300° C. After a residence time, thebiomass partially decomposes, giving off volatiles such as syngas.Accordingly, torrefaction is commonly performed in the absence of oxygento prevent ignition of the biomass during torrefaction. The processproduces a final product known as “torrefied biomass” or “torrefiedwood” when produced from woody biomass. Torrefaction offers a promisingbiomass upgrading option, as the physical properties of the torrefiedsolids are similar to those of coal.

During torrefaction, the hemicellulose is the removed to a greaterextent than the other components of the biomass. The hemicellulosedisplays an initial rapid decomposition rate followed by a more lengthysecondary charring with increased holding time. Portions of lignin havebeen observed to decompose or transform during torrefaction, whilecellulose maintains its crystalline structure. The removal ofhemicellulose results in a physiochemical transformation of the solidwoody biomass material. Elemental analysis of torrefied wood has shownthat the fractional makeup of carbon is increased by up to 15-20% whileoxygen is reduced by up to 50%. As a result, the atomic ratios of H/Cand O/C are reduced from approximately 1.64 to 1.11 and from 0.82 to0.49, respectively.

The resulting torrefied wood solids offer great promise in renewablecombustion opportunities and syngas production due to their increasedenergy value, friability, and hydrophobic nature. Densification andpelletization of the torrefied solids are desirable to improve ease ofhandling and storage of the fuel product, i.e., by transforming theproduct into uniform, high-density pellets; however, these processesexperience many problems.

Conventional wisdom suggests that because much of the originalhemicellulose is liberated during the torrefaction process, thereremains a higher proportion of lignin on a per unit basis of total solidmass than before the reaction occurred. Therefore, adequate amounts oflignin remain to sufficiently bind the solids during pelletization ordensification. However, at the reaction temperatures necessary tocomplete torrefaction, the glass transition temperature of the lignin isaltered. In other words, the temperature required to initiate re-bondingof the lignin is increased. The absence of water, considered to be apositive attribute in the torrefaction process, is also believed to playa role in altering the glass transition temperature of the remaininglignin.

In an effort to reach higher temperatures to achieve reactions with theresidual lignin to bind the solids, conventional pellet presses wouldhave to be operated at temperatures beyond current technological limits.While several technologies offer promising results for making hightemperature pellets, these technologies are tedious, expensive, andpresently unavailable for commercialization.

High-temperature operation introduces another serious drawback topelletization, namely syngas production. As higher temperatures arereached in an effort to initiate lignin reactivity, the previouslyreacted materials liberate significant amounts of syngas composed of amixture of carbon monoxide, hydrogen, carbon dioxide, methane, nitrogen,and small amounts of hydrocarbons. This thermo-chemical conversion isfurther encouraged by the altered friability of the remaining solids,which is now much greater, and by a solids particle size that is quicklyreduced to micron size as the solid is introduced to the feed rollers,pellet rams or pellet dies. The resulting product is an ultra-fineparticle with a greater surface area than that of the original torrefiedsolids and consequently is highly pyrophoric. While desirable for theend use of the product, the pyrophoric nature of the product creates ahazard to personnel and equipment during the densification andpelletization process and remains problematic for the successfulformation of torrefied pellets.

To avoid the drawbacks associated with high-temperature pelletization,processes that allows for the densification and pelletization oftorrefied biomass, hydrothermal carbonized biomass, and other charswithout the use of temperatures exceeding the technological limits ofconventional pellet presses have been developed. However, it wasdiscovered that low-temperature pelletization utilizing a binder as asubstitute for the lignin also involved many challenges and drawbacks.Specifically, it was found that once a pelletization unit reachestemperatures adequate for pellet formation, explosions and hollow corepellets occur, despite operating temperatures well below the flashpointof torrefied wood. Without intending to be bound by a particular theory,it is believed that fine particles of torrefied wood in the pelletizeremit hydrogen gas and carbon monoxide even at very low temperatures,resulting in highly pyrophoric properties. While considerable teachingexists in the literature regarding the liberation of torrefaction gases,this discovery was surprising.

It was discovered that lower pelletization temperatures combined with aninert environment yield less spontaneous and unintentional combustionreactions during pelletization and result in an improvement in machineuptime and yield. It is believed that this limits the amount of syngasproduced during the pelletization process and offers the user anopportunity to operate an array of pelletization equipment in theabsence of increased syngas hazards.

To maintain margins of safety with the finished pelletized product, theformation of robust pellets is necessary to reduce the pyrophoric natureof the product. It was found that properly formed pellets or briquetteswill significantly reduce the fire hazard by removing the small particlesizes prone to spontaneous combustion. The robustness of the pellet isnecessary to maintain this density during storage and transportation. Ifparticle size is allowed degrade to a small fraction in an oxygen richenvironment, the risk of unintentional combustion will likely increasedue to continued liberation of syngas.

In one aspect, a method is provided for producing a pelletized fuelproduct, which includes pelletizing at least partially carbonizedbiomass in an inert atmosphere. In certain embodiments, the at leastpartially carbonized biomass comprises torrefied wood or hydrothermallycarbonized wood. The at least partially carbonized biomass may alsoinclude coal and/or char. In one embodiment, the method includesapplying a binder to the at least partially carbonized biomass prior tothe step of pelletization. The binder may be a starch-based binder or awaterproof binder. For example, the binder may include defatted orfull-fatted soybeans. In one embodiment, the binder may be as describedin pending U.S. patent application Ser. No. 13/367,138, filed on Feb. 2,2012 and entitled “Methods For Producing Binders and CombustibleComposite Materials and Compositions Produced Therefrom,” which isincorporated herein by reference in its entirety.

In certain embodiments, the inert atmosphere includes an inert gasselected from the group consisting of nitrogen, carbon dioxide, andsteam. For example, the inert atmosphere may include steam produced fromevaporation of water contained in or on the biomass. Evaporation of thewater from the biomass may be caused by the high temperature in thepelletizer. Other inert gasses may also be used. The inert atmospheremay be substantially free of excess oxygen.

In one embodiment, the inert atmosphere includes an oxygen displacingfluid. For example, the inert atmosphere may include an oxygendisplacing foam or other material that renders the pelletizersubstantially oxygen-free. In one embodiment, the inert atmosphereincludes a glycerin foam, alone or in combination with an inert gas.Other foams may also be used. For example, an inert gas may be used tofoam a foaming material. The foam may aid in capturing the inert gas andmaintaining the inert gas with the at least partially carbonized biomassduring subsequent processing.

In certain embodiments, the method includes applying water to the atleast partially carbonized biomass prior to the step of pelletization.In one embodiment, the method includes applying a first amount of waterto the at least partially carbonized biomass prior to the step ofpelletization. For example, the first amount of water may be applied tothe biomass upstream of the binder, downstream of the binder, orsimultaneously with the binder. In one embodiment, the binder and thefirst amount of water are provided to the biomass together, such as froma single source or a mixer. In certain embodiments, the binder is mixedwith water prior to being applied to the biomass, or is provided to thebiomass with water other than the first amount of water. For example,the first amount of water may be effective to disperse the bindersubstantially evenly across the biomass prior to pelletization.

In certain embodiments, the first amount of water is effective topenetrate pores of the at least partially carbonized biomass. Forexample, the first amount of water may penetrate the pores of torrefiedwood biomass, creating a mixture of embedded moisture and binder, tofacilitate optimized binding. The embedded water may be evaporated outof the biomass in the pelletization or drying processes.

The first amount of water applied to the biomass may be adjusted basedon the type of torrefaction or carbonization reactor that is used toproduce the at least partially carbonized biomass. For example, thefirst amount of water may be used to quench the dry biomass exiting thereactor to prevent self-ignition. In one embodiment, the first amount ofwater is applied to torrefied wood exiting a torrefaction reactor.

In one embodiment, the first amount of water is effective to give the atleast partially carbonized biomass an embedded moisture content of fromabout 10 percent to about 40 percent, from about 10 percent to about 30percent, from about 10 percent to about 20 percent, from about 20percent to about 40 percent, or from about 25 percent to about 40percent by weight. For example, the first amount of water may beeffective to give the at least partially carbonized biomass a moisturecontent of about 22 percent to about 32 percent by weight.

In certain embodiments, where the at least partially carbonized biomasscontains moisture, the step of pelletizing may produce steam from thebiomass that acts as at least a portion of the inert gas of the inertatmosphere.

In certain embodiments, the method includes applying a second amount ofwater to the at least partially carbonized biomass prior to the step ofpelletizing. For example, the second amount of water may be applied tothe biomass independently from the first amount of water. For example,the second amount of water may be applied downstream of the first amountof water and prior to the pelletization step.

In certain embodiments, the second amount of water is applied to thebiomass immediately prior to the biomass being pelletized. For example,the second amount of water may be applied just before the biomass entersthe pelletizer. In one embodiment, the second amount of water is appliedto the carbonized biomass at a distance upstream of the pelletizer suchthat the second amount of water is substantially maintained as surfacewater on the biomass entering the pelletizer.

In certain embodiments, the second amount of water is applied such thata substantial portion of the second amount of water does not penetratepores of the at least partially carbonized biomass prior to the step ofpelletizing. For example, the second amount of water may be applied suchthat it remains on the surface of the biomass and does not becomeembedded as the first amount of water. Without being bound by aparticular theory, it is believed that the first amount of water maysaturate or fill the pores of the biomass such that the second amount ofwater remains on the surface of the biomass. Also, the timing of thesecond amount of water being applied immediately before pelletizationmay not allow the second amount of water to become embedded in the poresof the biomass.

It is believed that the second amount of water operates to reduce thetemperature of the pelletizing chamber. This increases productivity ofthe pelletizer and reduces friction within the pelletizing chamber(e.g., by reducing friction of the pelletizing dies). The second amountof water also reduces dust and the loss of carbonized material fromescaping dust.

The second amount of water may also control the moisture content of thecarbonized biomass cake to prevent plugging of the pelletizer and otherissues. For example, if the biomass cake in the pelletizer is too dry,the resulting pellets are too short and are prone to fracture. If thebiomass cake in the pelletizer is too wet, the pelletizer may be toocool and produce in weak pellets. Thus, the second amount of wateradvantageously allows for additional control of the pelletizationprocess by controlling the consistency of the biomass cake presented tothe pelletizer. That is, the second amount of water may be used to trimthe process and keep the system function within statistical processcontrol capabilities.

Additionally, at least some of the second amount of water may evaporatewithin the pelletizer to provide at least a portion of the inert gas.Additional inert gas may or may not be required by the pelletizer.

In one embodiment, the second amount of water is effective to bring amoisture content of the at least partially carbonized biomass to about25 percent to about 60 percent, from about 25 percent to about 55percent, from about 40 percent to about 55 percent, or from about 30percent to about 50 percent by weight. For example, the second amount ofwater may be provided such that the first amount of water, anyadditional water applied with the binder, and the second amount of waterare collectively present in an amount from about 45 to about 55 percentby weight. In one embodiment, the second amount of water may provideabout a 10 percent to about a 40 percent increase in moisture content byweight. That is, about 10 to about 40 percent moisture by weight may beunembedded surface water.

In one embodiment, a method for producing a pelletized fuel productincludes: (i) applying a binder to the at least partially carbonizedbiomass, (ii) applying a first amount of water to the at least partiallycarbonized biomass, (iii) applying a second amount of water to the atleast partially carbonized biomass after applying the binder and thefirst amount of water, and thereafter (iv) pelletizing the at leastpartially carbonized biomass in an inert atmosphere. For example, theinert atmosphere may include steam produced from evaporation of thefirst amount of water and/or the second amount of water.

In certain embodiments, the method also includes applying oil to the atleast partially carbonized biomass before or during the pelletizing. Forexample, the oil may include soybean oil, vegetable oil, canola oil,ethylene glycol, hydrocarbons, or the like.

In certain embodiments, the method also includes at least partiallycarbonizing a biomass feed to produce the at least partially carbonizedbiomass. For example, the step of at least partially carbonizing abiomass feed comprises torrefying the biomass feed or hydrothermallycarbonizing the biomass feed. For example, the biomass feed may includewood.

In another aspect, an apparatus for producing a pelletized fuel productis provided. As shown in FIG. 1, the apparatus 10 includes a feeder 12of at least partially carbonized biomass, a pelletizer 14 configured toreceive and pelletize the at least partially carbonized biomass, and aninert gas source 16 configured to provide inert gas to the pelletizer14. In certain embodiments, the at least partially carbonized biomassincludes torrefied wood or hydrothermally carbonized wood. In oneembodiment, the inert gas includes nitrogen, carbon dioxide, or steam.

In certain embodiments, the pelletizer 14 includes one or more of thefollowing components: a pelletizing chamber 22, a pelletizing discharge24, a conveyance to cooling chamber 26, and a cooling chamber 28. In oneembodiment, the pelletizer at least includes pelletizing chamber 22. Thepelletizing chamber 22 may include any known pellet-producing mechanism.For example, the pelletizing chamber may be a small ring die pelletmill, a commercial scale ring die pellet mill, a punch-and-die pelletmachine, a pellet press, or the like. For example, the die may be an 8mm die.

Inert gas source 16 may be configured to provide inert gas to any or allcomponents of pelletizer 14. Separate inert gas sources may also provideinert gas to the individual components of the pelletizer. The inert gassource may also include the moist biomass itself. For example, moistbiomass may be provided to the pelletizer and the high temperaturestherein may produce steam from the water on or in the biomass.

In one embodiment as shown in FIG. 1, the apparatus 10 includes a firstwater source 20 configured to moisten the at least partially carbonizedbiomass to a moisture content of at least about twenty percent prior topelletization. For example, the first water source 20 may be configuredto moisten the at least partially carbonized biomass to a moisturecontent of about 20 percent to about 40 percent by weight prior topelletization. In one embodiment, the first water source 20 isconfigured to moisten the at least partially carbonized biomass to amoisture content of about 22 percent to about 32 percent by weight.

The apparatus 10 also may include a binder source 18 configured tointroduce a binder to the at least partially carbonized biomass prior topelletization. For example, the binder may be introduced to the at leastpartially carbonized biomass such that the biomass contains binder in anamount from about 0.5 percent to about 15 percent, from about 1 percentto about 10 percent, or from about 2 percent to about 5 percent byweight of the at least partially carbonized biomass. In one embodiment,the biomass may contain binder in an amount of about 2.5 percent byweight of the at least partially carbonized biomass.

The apparatus 10 may also include a second water source 21 configured tofurther moisten the at least partially carbonized biomass. In oneembodiment, the second water source 21 is configured to bring a moisturecontent of the at least partially carbonized biomass to about 40 percentto about 60 percent by weight. For example, the first water source 20may bring the moisture content of the biomass to about 20 to about 40percent by weight, and the second water source 21 may bring the moisturecontent of the biomass to about 40 to about 60 percent by weight. In oneembodiment, the second water source 21 is configured to bring themoisture content of the at least partially carbonized biomass to about45 percent to about 55 percent by weight.

In certain embodiments, the second water source 21 is configured toapply water to the at least partially carbonized biomass immediatelyprior to the at least partially carbonized biomass being pelletized bythe pelletizer 14. For example, the second water source may be upstreamof the pelletizer 14 and downstream of the first water source 20 and/orthe binder source 18.

In one embodiment, the binder source 18 and the first water source 20are configured to provide the binder and the first amount of water tothe at least partially carbonized biomass simultaneously. In anotherembodiment, the first water source is upstream or downstream of thebinder source.

In one embodiment, as shown in FIG. 1, an apparatus for producing apelletized fuel product includes a feeder 12 of at least partiallycarbonized biomass, a binder source 18 configured to provide a binder tothe at least partially carbonized biomass, a first water source 20configured to moisten the at least partially carbonized biomass to amoisture content of about 20 percent to about 40 percent by weight, asecond water source 21 configured to bring the moisture content of theat least partially carbonized biomass to about 40 percent to about 60percent by weight, a pelletizer 14 configured to receive and pelletizethe at least partially carbonized biomass, and an inert gas source 16configured to provide inert gas to the pelletizer. For example, theinert gas may at least partially include steam produced from theevaporation of moisture from the at least partially carbonized biomass.

In certain embodiments, as shown in FIG. 2, the apparatus 50 alsoincludes a feeder 52 of raw biomass and a reactor 54 configured toreceive and at least partially carbonize the raw biomass. For example,the reactor may be a torrefaction reactor or a hydrothermalcarbonization reactor. For example, the raw biomass may include wood.

As shown in FIG. 2, in one embodiment, the apparatus 50 also includes anoil source 65 configured to provide oil to the at least partiallycarbonized biomass prior to or during pelletizing. The oil may be addedto the carbonized biomass feedstock cake in pelletizer when the cakeplugs the pelletizer. The oil advantageously unplugs the pelletizer andmoves the dry cake plug through the pelletizer to keep the processrunning. The oil source may provide the oil to the pelletizer or biomassin small bursts. For example, the oil may be provided in an amount ofabout 1 percent to about 5 percent by weight of the biomass.

The methods and apparatuses of the present disclosure produce torrefiedwood pellets at three times the capacity of comparable “dry” torrefiedwood systems. For example, commercial scale pelletizing plants disclosedherein may pelletize 4.5 tons per hour of raw wood, while conventionalprocesses produce 1.2-1.3 tons per hour of torrefied wood.

Publications cited herein and the materials for which they are cited arespecifically incorporated by reference herein. Modifications andvariations of the products, methods, and apparatuses described hereinwill be obvious to those skilled in the art from the foregoing detaileddescription. Such modifications and variations are intended to comewithin the scope of the appended claims.

We claim:
 1. An apparatus for producing a pelletized fuel product,comprising: a feeder of raw biomass; a reactor configured to receive theraw biomass and to produce at least partially carbonized biomass; afeeder of at the least partially carbonized biomass; a binder sourceapparatus configured to provide a binder to the at least partiallycarbonized biomass; a first water source configured to moisten the atleast partially carbonized biomass to a moisture content of about 22percent to about 32 percent by weight; a second water source configuredto bring a moisture content of the at least partially carbonized biomassto about 45 percent to about 55 percent by weight; a pelletizerconfigured to receive and pelletize the at least partially carbonizedbiomass; a cooling chamber operatively connected to the pelletizer by aconveyance; and an inert gas source configured to provide inert gas tothe pelletizer, wherein the second water source is configured to applywater to the at least partially carbonized biomass immediately prior tothe at least partially carbonized biomass being pelletized by thepelletizer.
 2. The apparatus of claim 1, further comprising: an oilsource configured to provide oil to the at least partially carbonizedbiomass prior to or during pelletizing.
 3. The apparatus of claim 1,wherein the at least partially carbonized biomass is pelletized in aninert atmosphere, and wherein a portion of the inert atmospherecomprises steam produced from evaporation of the first amount of waterand/or the second amount of water.
 4. An apparatus for producing apelletized fuel product, comprising: a feeder of raw biomass; a reactorconfigured to receive the raw biomass and to produce at least partiallycarbonized biomass; a feeder of the at least partially carbonizedbiomass; a binder source configured to provide a binder to the at leastpartially carbonized biomass; a first water source configured to moistenthe at least partially carbonized biomass to a moisture content of about20 percent to about 40 percent by weight; a second water sourceconfigured to bring the moisture content of the at least partiallycarbonized biomass to about 40 percent to about 60 percent by weight; apelletizer configured to receive and pelletize the at least partiallycarbonized biomass; a cooling chamber operatively connected to thepelletizer by a conveyance; and an inert gas source configured toprovide inert gas to the pelletizer, wherein the second water source isimmediately upstream of the pelletizer, and is configured to apply waterto the at least partially carbonized biomass immediately prior topelletizing.
 5. The apparatus of claim 4, wherein the binder source andthe first water source are configured to provide binder and water to theat least partially carbonized biomass simultaneously.
 6. The apparatusof claim 4, wherein the inert gas comprises steam produced fromevaporation of moisture from the at least partially carbonized biomass.7. The apparatus of claim 4, further comprising: a feeder of rawbiomass; and a reactor configured to receive and at least partiallycarbonize the raw biomass.
 8. The apparatus of claim 4, wherein thereactor is a torrefaction reactor or a hydrothermal carbonizationreactor.
 9. The apparatus of claim 4, wherein the at least partiallycarbonized biomass is pelletized in an inert atmosphere, and wherein aportion of the inert atmosphere comprises steam produced fromevaporation of the first amount of water and/or the second amount ofwater.